No prayers at government meetings, that’s sacred and belongs to religions. Grammatically, the use of “an” in front of “establishment of religion” makes the amendment about respecting that which is established by religion. Not about establishing a religion. It separates church and state. It disallows government from appropriating that which is sacred and within the purview of religions.
The founding fathers realized that government profanes religion, it trespasses on religion. So they forbade government from associating itself with religious forms, practices, or creeds. This is how the Supreme Court interprets the “Establishment” clause, it’s about government favor or “respecting” things that are within the purview of religious views.
So pray in you choosen place of worship or at home, not in government.